E. Rossoni places this surname in Palermo, Altofonte and Gela, and considers its etymological origin doubtful. He proposes two hypotheses: one links it to a mistaken transcription of the ancient name Gnossus, the Cretan city of Knossos; the other relates it to the medieval Germanic gnafen ("to scratch oneself"), from which a nickname would have arisen.

V. Blunda, by contrast, proposes a Sicilian dialect origin: the surname would derive from the word gnòfu, which in that dialect designates someone of great bulk. On this reading, the surname would have originated as a nickname applied to a person of voluminous or massive build, following the usual register of Sicilian nicknames drawn from physical bearing.